Natural gas has been used as fuel for internal combustion engines in consist locomotives. Because natural gas has a lower volumetric energy density than traditional fuels, such as diesel and gasoline, the natural gas used by the locomotives is generally only practical to store in a liquefied state (“LNG”). At atmospheric pressures, the natural gas must be chilled to below about −160° C. to remain in liquid form. Consists having LNG-fueled locomotives store the LNG in insulated tank cars (a.k.a., tender cars) that are towed by the locomotive.
In order to be utilized as an effective engine fuel, liquefied natural gas requires more energy than a liquid counterpart to be stored, compressed, vaporized and transported within a train consist. This relatively greater amount of energy required to power ancillary equipment is typically drawn from the power output of the consist's main engine. The additional consumption of power results in undesirable consequences with regards to fuel efficiency and engine power availability.
One method of improving fuel and engine power efficiencies is described in U.S. Patent Publication No. 2010/0186619 (“the '619 publication”) of Kumar that published on Jul. 29, 2010. The '619 publication describes locomotives and rail cars that have the capacity to generate electrical power from dynamic braking, to store the power, and to use the power at a later time during motoring. In particular, the '619 publication describes storing electrical power generated from dynamic braking in an energy capture and storage system. The energy capture and storage system effectively utilizes electrical energy that, in previous consist designs, was dissipated away on resistive grids. The energy is used to power traction motor/propulsion systems, for as long as the energy lasts.
Although the system of the '619 publication may be capable of making use of previously wasted electrical energy, it does not present solutions for alleviating the load on a consist's main engine that is related to the storage, processing and distribution of liquefied natural gas.
The system of the present disclosure solves one or more of the problems set forth above and/or other problems with existing technologies.